Mechanical presses, particularly gang presses



C. HQLZER Filed Dec. 7, 1959 MECHANICAL PRESSES, PARTICULARLY GANG PRESSES April 24, 1962 wmvra/e United States Patent Ofifice 3,30,878 Patented Apr. 24, 1962 3,030,878 MECHANICAL PRESSES, PARTICULARLY GANG PRESSES Carl Hiilzer, Solingen, Germany, assignor to Th. Kieserling & Albrecht, Solingen, Germany Filed Dec. 7, 1959, Ser. No. 857,954 Claims priority, application Germany Dec. 8, 1958 4 Claims. (Cl. 100-237) The present invention relates to mechanical power presses in general, and more particularly to a so-called gang press in which a series of rams may be reciprocated into contact with the work, either simultaneously or in any given sequence.

In a known power press, all Working rams are mounted on a common carrier, usually by means of shifting or reciprocating devices in the form of connecting rods which constitute a crank drive. The carrier, i.e. a crankshaft, is driven by toothed gears at one or more points and, particularly if the press comprises a large number of rams, is subjected to considerable torsional stresses. These and other stresses increase with the length of the crankshaft. A drawback of such presses is that long crankshafts are rather expensive because of well-known technical problems connected with their manufacture. In order to avoid the use of long crankshafts, proposals were already made to drive the connecting rod of each ram by a separate crankshaft and to mount such short crankshafts in the press frame in such a manner that they are free to rotate with respect to each other. Each crankshaft is connected with a ring gear which meshes with toothed gears on a drive shaft or an intermediate shaft. Such arrangement facilitates the use of very short and more resistant crankshafts.

In certain other known mechanical presses, particularly in extrusion presses utilized for the mass-manufacture of comparatively small, light extruded products, the individual rams are driven by separate drives which comprise cam plates, cranks or the like.

A serious disadvantage common to the above described prior constructions is that the movements of all ramreciprocating means and of their carriers in a direction toward the work are simultaneous. Consequently, the frame of the press and the required angular momentum must be dimensioned by full consideration of the combined pressure requirements of all working rams which, inturn, necessitates very heavy frames and considerable power, resulting in greatly increased cost of such presses.

An important object of the present invention is to provide a power press which may operate with a large number of rams in a frame of extremely lightweight construction.

Another object of the invention is to provide a press of the above outlined characteristics which is constructed in such a way that a large number of rams may be operated by a very light drive which requires little power for its operation, such as corresponds to a fraction of the total power necessary if all the rams were put to action at the same time.

A further object of the invention is to provide a gang press which is constructed in such a way that the total energy required for its operation need not always exceed the power requirements of a single ram.

A concomitant object of the present invention is to provide a power press of the type described hereinabove which is constructed in such a way that the length of strokes performed "by the individual rams may be readily adjusted and in which the relative position of the rams may be varied at will so that the sequence in which the rams are applied against a workpiece may be controlled as desired.

A still further object of the instant invention is to provide a press in which any selected ram or rams may be disconnected from the drive in a very simple and convenient manner.

With the above objects in view, the invention resides essentially in the provision of a press which comprises a series of reciprocable rams each connected with its own strap, and wherein the position of each strap with respect to the other strap or straps may be changed at will. To that end, the straps are rotatably mounted on the eccentrics of separate spur wheels which latter are rotatably carried by an axle and may be brought into and out of mesh with a set of gears on the drive shaft of the press. The gears on the drive shaft are preferably releasably connected to the latter, or the drive shaft with the gears may be axially displaced with respect to the spur wheels. Owing to such adjustability of the straps with respect to each other, the sequence in which the rams are applied against a workpiece may be selected in a way that a ram exerts pressure only when the other rams are out of contact with the work, i.e. the total power necessary for operating the press need not exceed the power requirements of a single ram. In other words, the maximum power required for operation of the improved press need not exceed the power requirements of that ram which exerts maximum pressure when applied against a workpiece.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following detailed description of a specific embodiment when read in connection with the accompanying drawing the single illustration of which is a partly front elevational and partly sectional view of the press embodying my invention.

Referring now in greater detail to the drawing, there is shown a press comprising a frame which includes a pair of spaced uprights or posts 1, 2 connected with each other by a table or platen 3, by a pair of horizontal crossheads 4, 4a above the table, and by a horizontal axle 5 above the upper crosshead 4a. The upper ends of uprights 1, 2 rotatably support a horizontal drive shaft 6. The press further comprises four rams 7a, 7b, 7c, 7d which are vertically reciprocable in thelower crosshead or bar 4. Each ram is connected to its own push rod 9 by a spindle 8. The push rods are slidably guided'in the upper crosshead or bar 4a, and each thereof is articulately fixed to its own eccentric 10.

The axle 5 supports four freely rotatable gears in the form of spur wheels 11 each of which is formed with an eccentric fiange 11a rotatably mounting a strap 10. The spur wheels 11 are adapted to mesh with the gears 12 which are non-rotatably fixed to the drive shaft 6,, e.g. by means of removable wedges 13 or the like. The gears 12 are axially slidable along the shaft 6 so as to be movable out of mesh with the respective toothed wheels 11. In this manner, the angular position of a selected spur wheel 11 may be adjusted with respect to the other wheels, for example, in such a way that the rams 7a7d will be moved into and away from contact with the nonrepresented work on the platen or table 3 in a given sequence. All that is necessary is to remove the selected wedge 13 and to thereupon axially shift a gear 12 out of mesh with the corresponding gear wheel 11 to permit rotation of the latter into desired angular position.

The angular position and the distance of individual rams 7a7d from a work on the platen 3 may be adjusted by means of worm drives each of which comprises a worm wheel 15 fixed to the lower end of a spindle 8 and a worm shaft 14 which is rotatably mounted in the ram and meshes with the respective worm wheel. By rotating the shaft 14, the corresponding worm wheel 15 and spindle 8 will be rotated with respect to the push rod 9 so as to axially displace the corresponding ram with respect to its push rod. The shaft 6 is driven by one or more sprockets 16.

It will be readily understood that, owing to the above described construction of my press, the frame 1, 2, 3, 4, 4a, may remain of lightweight design even if the press comprises a large number of rams and even if the individual rams must exert considerable pressure upon the work. Also, the drive for the rams need not require more power than is necessary to operate a single ram, i.e. the one with maximum power consumption.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A press comprising a frame; a plurality of rams reciprocably mounted in said frame; a drive shaft rotatably mounted in said frame; an axle parallel with said shaft and supported in said frame; a plurality of first gears, one for each ram and each rotatably mounted on said axle, each of said gears comprising an eccentric; a plurality of second gears, one for each of said first gears and each mounted on said drive shaft so that the second gears may mesh with the respective first gears;- means for adjustably connecting the second gears with said drive shaft in such a manner that, in a first condition of adjustment of said second gears, the first gears are driven by said drive shaft through the second gears and that, in a second condition of adjustment of said second gears, the first gears are freely rotatable with respect to the drive shaft whereby selected first gears may be angularly adjusted with respect to the other first gears; and a plurality of straps, one for each of said eccentrics, each strap articulately connected with one of said rams and each rotatably mounted on the respective eccentric to positively reciprocate the rams in two opposite directions when the drive shaft rotates and the second gears are in said first condition of adjustment.

2. A press as set forth in claim 1, wherein the means for adjustably connecting the second gears with said drive shaft are wedges and the second gears are axially movable on said drive shaft into and out of meshing engagement with the respective first gears.

3. A press comprising a frame; a plurality of aligned rams reciprocably mounted in said frame; a drive shaft rotatably mounted in said frame; an axle parallel with said shaft and supported in said frame; a plurality of first gears, one for each ram and each rotatably mounted on said axle, each of said gears comprising an eccentric; a plurality of second gears, one for each of said first gears and each mounted on said drive shaft so that the second gears may mesh with the respective first gears; means for adjustably connecting the second gears with said drive shaft in such a manner that, in a first condition of adjustment of said second gears, the first gears are driven by said drive shaft through the second gears and that, in a second condition of adjustment of said second gears, the first gears are freely rotatable with respect to the drive shaft whereby selected first gears may be angularly adjusted with respect to the other first gears; a plurality of straps, one for each of said eccentrics and each rotatably mounted on the respective eccentric;'and means for articulately and adjustably connecting said straps with said rams so that the straps may positively reciprocate the rams in two opposite directions when the drive shaft rotates and the secondgears are in said first condition of adjustment.

4. A press as set forth in claim 3, wherein the means for articulately and adjustably connecting said straps with said rams comprises push rods each articulately connected with one of said straps, worm wheels each having a spindle axially adjustably connected with one of the push rods, each worm wheel rotatably mounted in the respective ram, and a worm rotatably mounted in each ram, each of said Worms meshing with the respective worm wheel and adapted to rotate the same so as to adjust the axial position of the respective spindle.

References Cited in the file of this patent UNITED STATES PATENTS 46,278 Stone Feb. 7, 1865 79,605 Sibley July 7, 1868 576,619 Rouse Feb. 9, 1897 989,373 Lindgren Apr. 11, 1911 1,138,799 Scott May 11, 1915 2,135,381 Blaser Nov. 1, 1938 FOREIGN PATENTS 528,497 Great Britain Oct. 30, 1940 

